Insulator.



severe mechanical shocks.

"UNITED sTATiis PATENT OFFICE.

f BAY I. JACKSON, or EDCEWOOD PARK, PENNSYLVANIA, AssIeNoR To WESTINGHOUSE ELECTRIC ANI) MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

INSULATOR.

Specification of Letters Patent.

Patented sept; 12, 1916.

Application and october a, 1914. -seriai No. 864,56?

To all'fwhom 'it may concern vBe it known that I, RAY P. JACKSON, a citizen of the United States, and a resident 'of Edgewood Park, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Insulators, of which the following is a specification.

My invention relates to electrical insulating bodies or structures, and it has special reference to insulators which are adapted for outdoor installation and exposure to severe mechanical and electrical service conditions.

At present, the usual insulators are made entirely of unprotected porcelain members which are nested into one another and cemented together. This type of construction necessarily makes such insulators fragile andliable to breakage when subjected to Moreover, it is practically impossible torepair these whole porcelain insulators when one of the nested porcelain piecesbecomes cracked or rupit with a new .member without breaking the remaining porcelain members to which the defective member is securely cemented. Also, whole porcelain insulators usually depend .for their insulating properties upon long leakage paths between the conductors that are to be insulated and the ground. Consequently, portions of such insulators are subjected'to abnormal electrical stresses resulting from the concentrations thereupon of the electrostatic lines which comprise the electric fields existing between the conductors to beinsulated and the ground, and

' .which surround the insulators. If provision can bev made for distributing the electrol static lines substantially uniformly upon the surfaces of the porcelain insulators to preclude concentrations thereupon of abnorg mally high electrical stresses, the insulators may be safely utilized for higher voltages than' has heretofore been deemed advisable.

One object of my invention is to provide an' insulator comprising members of porcelain or some other material of high dielec tric strength, which members are so disposed as to provide a built-up structure but wherein the' members may be easily replaced when any one of them becomes defective, without requiring the whole insulatured, because of the difiicu'lty in replacing tonto be scrapped ,or theconductor, 'which is insulated, to be disconnected from the l liliv insulator while making replacements of the injured insulating members.

Another object of myinvention is to pro;

vide an insulatingl 'structure that Vis particu` larly adapted for seyere service conditions by affording-protection .to the lfragile-portions, which usually constitute the insulat- I ing portions, against mechanical blows;

f A further Object -of my 'invention is to provide an insulator which may be'fused forvery high-voltage service conditions for the reason that its insulating portions will not be subjected to abn'rmal concentrations of electrostatic stresses.

Gther features of novelty will be described and pointed out in-thefollowing specification and appended claims to which reference may now be had.

Figure 1 is a. view, partially in elevation and partially in section, of an insulator embodying, a form of my invention, and

Fig. 2 is a cross-sectional view of a modifiedv form of the insulator shown in Fig. 1.

Referring to Fig. l, the insulator comprises a plurality of superposed insulating members 1, which are preferably -made of porcelain, and metallic supports 2 that provide caps 3 which embrace top portions 4 of the members 1.` Each support Q is also provided with an upwardly extending portion 5 which projects into a recess formed in the top portion 4 of the porcelain member 1 located above it. Bodies of cement 6 hold each porcelain member 1 firmly between the extending portion 5 of one support 2 and the portion 8 of the next succeeding support. In this manner, a rigid structure is secured by means of which considerable weight may be supported. A metallic cap 7 is disposed on the top porcelain member 8 and is provided with a connector 9 to l which an electrical conductor, which it-is desired to insulate, may be connected. Af

v preferably as shown in the drawing, be ng provided, at their lower ends,w1th`conically fiared petticoats. The members lbeing made of fragile in aterial, 'such as'porcelain, are

'for securing the built-up capable ot' witl'istanding compressive stresses only and, therefore, they are interposed between portions of the metallic members :2 which resist the main mechanical stresses imposed upon the insulating structure. inasmuch as the porcelain members l resist all the electrical stresses imposed upon the structure, they are liable to breakage because ot iaslroyers and mechanical defects which are greatly exaggerated -when the porcelain members are-subjected to electrical stresses.

To insure a substantiall)7 uniform distribution of electrostatic stresses upon the insulator shown in Fig. l (as will be hereinafter described). metallic petticoats are provided on'the metallic supports 2, such as are indicated at 15P. It will be apparent that the metallic pettieoats 19a allord protection to the insulating members l also against mechanical blows. As a result, insulators made in accordance with my invention may be installed where the mechanical and electrical service conditions are very severe.

ln Fig. metallic supports l2, which are interposed between adjacent porcelain members l, comprise two detachable portions 13 and lvl. The upper portion 13, which pro `iects into the recess formed in the upper portion l oi the insulating member .l and which is secured thereto by the cement 6, is provided, at its lower periphery, with a flange or a plurality ot' spaced lugs l5. The lower portion 1l of the support l2 embodies a cap 1G which embracesythe upper portion -l of the next succeeding lower insulating member l. A flange 1i', integrally formed on the portion l-l, provides a seat tor the flange l5. Bolts 1S irmly hold the portions 13 and ll together, thereby insuring a rigid structure.

lt is apparent that, when a member l becomes detective, it may be detached from the structure by removing the bolts 1S which engage with the supports l2 immediately7 above and below the detective insulating member. In this manner, defective insulating membersmay be expeditiously7 and con'- veniently replaced by new insulating members without ali'ecting either the electrical or the mechanical properties of the built-up structure. i\loreo\er, it is unnecessary, during such replacing ot operationsI` to disconnect the conductor l) from the support.

I prefer that each ot the metallic membe s l2 be provided with conically flared portions lf) which constitute a series ot superposed metallic petticoats that alternate with the superposed insulating members l. As a result, a series ot comlensers is supplied, the conducting plates constituting the petticoats 19 and the dielectric between adjacent conducting plates comprising the porcelain members l. inasmuch as the petticoats lll conform substantially in, shape to the petti` coats of the insulating members i. a uniform distribution oiVl the electrostatic lines surrounding the built-np insulator is assured. It is well known that, i'l concentrations ot electrostatic stresses are precluded from -t'orming upon the insulating members i. the insulating members may be used to their tall insulating value and, consequently. the bailtup structure may be subjected to voltages which would otherwise. have been impossible without the use ot' the metallic petticoats lil. llvhile I have shown and described several. emliodiinents ot my invention. it will be understood that manymodilimtions may be made without departing trom the spirit thereot', and l desir(I that its .si-ope shall he limited only by the appended claims.

I claim as mjvf'finyention:

l. An insulator comprisingr a plurality olE superposed insulating members lmvingI outwardly-flared petticmits. and metallic supports therefor which are interposed betweem and rigidly secured to, adjacent insulatingl members, said supports being provided with portions that conform substantially to theI shape ot lsaid flared portions oi the insulating members.

f2. n insulator comprising a plurality oil super-posed and sin'iilarly shaped insulating` members which are conically llared. and rigid metallic supports interposed therebc tween and secured to adjacent insulating members, said metallic supports being proR vided witheonically tial-ed portions which contorni in shape substantially to that ol the conically-tiared portions ot the insulating members. l

3. :in insulator etmnirising a plurality ot' superposed insulating imanbersy ha vini; la red petticoat portions, and metallic suppl, z iuterposed therebetween and secured adto jacent insulating members', said metallic supports being provided with pelin-oat portions which contorni in shape substan4 tially to those ot' said insulatinja members in order to insure a substantially aniform distribution ot electrostatic t s, upon the surfaces ot the insulating meurbers.

el. An insulator cin'nprising au insulating member which is cenit-ally flared. and metallic members disposed above and ladow said insulating. mtanber` said metallic members being provided with `eonieally lll portions which are so shaptal as to coni. substantially to the shape ot coli portions of said insulati 1" member lla precludingI concentrations` ol electrostatic stress upon the insulator.

An insulator compri linga plurali superposed insulating` incinta s, and 'melah lic supports interposed between adjacent. members, said rigid metallic supp f prising upper portions which upper insulating members amt espoiuli lou tions which engage the lower insulating -members, the two portions of each support being exteriorly detachable.

' 6. An insulator comprisinga plurality of superpos'ed yinsulating members and rigid metallic supports interposed therebetween which are nested within one another and engage the upper portions of said insulating members in order to subject them to compressive stresses, each metallic support comprising two exteriorly detachable por tions, the upper one engaging the upper insulating member and the lower one engaging the4 lower insulating member.

7. An insulator comprising a plurality of superposed insulating members and rigid metallic supports interposed therebetween which are nested within one another and engage the upper portions of said insulating members in order to subject them to compressive stresses, each metallic support being provided with va portion that conforms substantially to the shape of .the insulating members and comprising two exteriorly detachable portions, the upper one engaging the upper insulating member'andthelower one engaging the lower insulating member.

8. An insulator comprising a plurality of superposed insulating members and rigid.

metallic supports interposed therebetween, each metallic support comprising two eXteriorly detachable portions, the upper 4one engaging the upper'insulating member and being nested Within the lower portionof the RAY l?. JACKSON.

Witnesses:

GoLmn- E. MCGEE, B., B. HINEs. 

